Preparation And Properties Of MoO_3-x Nanobelts For Anode Material Of Lithium Ion Batteries

With the further popularization of smartphone/tablet and notebook computers as well as other devices,the demand for lithium-ion batteries is growing,and the demands for the life and charging speed of lithium ion batteries?LIB?is further growing.How to improve the performance and cycle life of LIB is the problems to be addressed in this field.In the previous reports,there are many methods to improve the electrochemical performance of LIB,such as?1?preparation of special morphology or structure of micro/nano materials:the increasement of the specific surface area of the material leads lithium ion diffusion path shorten,which can improve the performance of LIB;?2?doping:doping increases the conductivity of the material.Introduction of heterogeneous ion,will play the role of grain refinement,this part of the function is similar to?1?;?3?compositing with conductive material?carbon or conducting polymer?:it can increase conductivity of anode material,and could also alleviate the volume change of material in the process of charge and discharge.In MoO₃ anode of LIB,although these methods can improve the electrochemical properties of LIB,but these methods are a little cumbersome.through an extremely simple"sauna action",a material containing oxygen vacancies are prepared,namely MoO_3-x.Material containing oxygen vacancies,increased conductivity of material,the performance of the electrochemical performance of MoO_3-x in LIB is more excellent than that of MoO₃.This paper has the following contents:1.a molybdenum trioxide containing oxygen vacancies,MoO_3-x has been prepared by sauna action.With the extension of heating time,material changes color from white to blue.2.as anode material for LIB,after the measurement of the charge/discharge cycling,cyclic voltammetry?CV?and electrochemical impedance spectroscopy?EIS?,we found in the 500 and 1000 mA g^-1,after 200 cycles,the specific capacity of MoO_3-x NBs is more than 2.5 times than that of MoO₃.Among them,at 500mA g^-1,the specific capacity of MoO3 NBs is 289 mAh g-1,while that of MoO3-x NBs is 729mAh g^-1.At 1000mA g^-1,the specific capacity of MoO₃ NBs is 150 mAh g^-1,while that of MoO_3-xNBs capacity is 410 mAh g^-1.This proves that the electrochemical properties of anode material of MoO_3-x NBs created by sauna action is better.3.XRD/XPS/TEM/UV-Vis/FT-IR/Raman analysis can prove that oxygen vacancies exist in the material.Oxygen vacancies and conductivity of material increased,which provided the basis to improve the electrochemical properties of the battery.Notably,the OVs and the resulting improved electrical conductivity could be used to account for their largely enhanced specific capacity and rate properties.On one hand,OVs lowered the energy barrier of Li⁺into the intralyer of MoO₆octahedron sheet layer and the interlayer of MoO_3-x,and provided extra lithium storage sites of MoO₃ during discharge-charge process.On the other hand,the improved conductivity of MoO_3-x provided efficient one-dimensional electron transport pathways.4.This study not only provides a new method for the preparation of MoO_3-x with rich OVs using a simple,environmentally friendly“sauna reaction”,but also indicates the importance of OVs in the largely enhanced electrochemical performance in MoO_3-x NBs,which may shed some light on the future development of electrode materials of lithium-ion batteries?LIBs?.